1. Field of the Invention
The present invention relates to a vehicle remote-operation apparatus which includes a radio portable unit allocated an identification code unique to a vehicle.
2. Description of the Background Art
In recent years, a remote-operation apparatus for a vehicle has been rapidly developed which is capable of opening and closing a door lock of the vehicle without inserting a key in a door of the vehicle.
FIG. 4, FIG. 6 and FIG. 8 are top views of a conventional vehicle remote-operation apparatus installed in a vehicle, showing its configurations. FIG. 5, FIG. 7 and FIG. 9 are diagrams, showing operational sequences of the conventional vehicle remote-operation apparatus.
In FIG. 4, in a vehicle, vehicle-outside antennas 11, 12, 13, 14 are provided near the door on the driver's seat side, near the door on the passenger-seat side, inside of or near a rear bumper on the driver's seat side and inside of or near the rear bumper on the passenger-seat side, respectively. Inside of the vehicle, vehicle-inside antennas 15, 16 are provided.
Herein, a conventional operation method will be described. First, a vehicle owner 5, holding a radio portable unit 4 allocated an identification code unique to a vehicle, comes close to the driver's seat and touches the door on the driver's seat side. Thereby, a door outside switch 2 on the driver's seat side is turned on, and this on-signal is transmitted to a control unit 1. Then, the control unit 1 transmits an authentication request signal, using the vehicle-outside antenna 11 (see FIG. 5(a)). At this time, if the portable unit 4 is located within a range 11A where the authentication request signal from the vehicle-outside antenna 11 can be communicated, the portable unit 4 transmits an authentication response signal (see FIG. 5(b)). Then, an authentication-signal receiver 8 receives this authentication response signal. If this is a code on record, a door-lock switch signal is transmitted to the control unit 1 (see FIG. 5(c)). Thereby, the door lock is opened.
As shown in FIG. 6, when the portable unit 4 is located in the rear of the vehicle, the control unit 1 transmits the authentication request signal using the vehicle-outside antenna 11 (see FIG. 7(a)). At this time, the portable unit 4 is out of the communicable range 11A of the authentication request signal from the vehicle-outside antenna 11. This disables the portable unit 4 from transmitting the authentication response signal. After a predetermined time has elapsed, the control unit 1 transmits the authentication request signal using the vehicle-outside antenna 13 (see FIG. 7(b)). Then, the portable unit 4 located within a range 13A where this authentication request signal can be communicated transmits the authentication response signal (see FIG. 7(c)). Sequentially, the authentication-signal receiver 8 receives this authentication response signal. This result is checked, the door-lock switch signal is transmitted to the control unit 1, and the door lock is opened (see FIG. 7(d)).
Furthermore, in the same way, if the vehicle owner 5 who is holding the portable unit 4 comes close to the passenger seat, a door outside switch 3 on the passenger-seat side is turned on, as well. Then, this on-signal is transmitted to the control unit 1. Sequentially, the control unit 1 transmits the authentication request signal, using the vehicle-outside antenna 12. At this time, if the portable unit 4 is located within the range where the authentication request signal from the antenna 12 can be communicated, the portable unit 4 transmits the authentication response signal. Then, the authentication-signal receiver 8 receives this authentication response signal. If this is a registered code, the door-lock switch signal is transmitted to the control unit 1, so that the door lock is opened.
Moreover, if the vehicle owner 5 holding the portable unit 4 approaches the vehicle from behind it, a door outside switch 7 on the vehicle-rear side is turned on. Then, this on-signal is transmitted to the control unit 1. Sequentially, the control unit 1 transmits the authentication request signal, using the vehicle-outside antenna 13 or 14. At this time, if the portable unit 4 is located within the range where the authentication request signal from the vehicle-outside antenna 13 or 14 can be communicated, the portable unit 4 transmits the authentication response signal. Then, the authentication-signal receiver 8 receives this, and if this is a registered code, the door-lock switch signal is transmitted to the control unit 1, so that the door lock is opened. Incidentally, for example, Japanese Patent Laid-Open No. 2003-106019 specification is known as a prior-art document related to the present invention.
However, in the above described conventional method, for example, when the vehicle owner 5 stays in the vehicle with holding the portable unit 4, if a third person touches the door outside switch 2 or the like as a switch for starting communication, communication may be executed to establish an authentication. This can fall into the opening of a door lock.
Therefore, as shown in FIG. 8, let's assume the vehicle owner 5 who is holding the portable unit 4 sits within a communicable range 15A of the vehicle-inside antenna 15, and that a third person 6 who does not have the portable unit 4 comes close to the vehicle and touches the door outside switch 2. At this time, using the vehicle-inside antennas 15, 16, the control unit 1 transmits a communication standby signal for not responding to the portable unit 4 to the communicable ranges 15A and 16A, respectively (see FIGS. 9(a) and 9(b)). Thereby, even if the door outside switch 2 is turned on, the door lock is not opened. Thereafter, in order to detect the portable unit 4 being located within the vehicle-outside communicable range, the vehicle-outside antenna 11 transmits the authentication request signal to the portable unit 4 (see FIG. 9(c)). At this time, the portable unit 4 is within the range of the vehicle-inside antenna 15, so that an authentication response is not made. This prevents the door lock from being opened, and thus, the third person 6 from opening the door.
However, even in this case, as shown in FIG. 9, the authentication time taken to communicate for the standby is equivalent to a time (T1×2+T2). Herein, T1 denotes the transmission time of the communication standby signal, and T2 designates the transmission time of the authentication request signal. As a result, even if the vehicle owner 5 who is holding the portable unit 4 touches the door outside switch 2, the total transmission time (T1×2) of the communication standby signal is added to the transmission time T2 of the authentication response signal. Hence, more time is taken, thus lengthening the processing time.